Navigation Reading Watchkeeping OnBoard

Watchkeeping

The 24-hours-period on board vessel is divided into 6 shift, or watches, as they are called.

Each watch last 4 hours.

The watches are

• First watch (2000 hrs – 24 hours)
• Middle watch (0000 hrs – 0400 hrs)
• Morning watch (0400 hrs- 0800 hrs)
• Forenoon watch (0800 hrs – 1200 hrs)
• Afternoon watch (1200 hrs – 1600 hrs)
• Evening watch (1600 hrs – 2000 hrs)

The evening watch is often divided into two watchs of 2 hours each to allowa everyone to enjoy the evening meal. This two watches are called the first and second dogwatch

The Radio Operator keeps watch four periods of two hours a day

One of the Watchkeeping-Systems that is used in the deck departement aboard sea-going vessels is the “4-12-8” system. Whereby the first mate stand all four-o’clock watches. The second mate stands the twelve-o’clock watches and the third mate stands the eight o’clock watches. The captain will often join the third mate, since the third mate is usually the least experienced officer.

Heading, course, track, and drift.

By Heading is understood the direction in which the vessel is pointing. It is the angle between the fore and aft line of the vessel and True North, expressed in degrees.

Heading constantly changes duet o sea and wind influences and steering error.

By Course is understood the intended sailing direction of the vessel in, other words

It is the direction in which the vessel is steered in order to reach her destination (B) It is expressed in degrees.

A Track consists of one, or a number of course, line along which the navigator intends to proceed for a safe passage, e.g when clearing a danger.

A Great Circle Course will form athe short connection between two places on the Earth.

A Rohumb Line Or Loxodrome, will form the line whereby all the angle made by the course line and the meridians are equal. This implies that in (mercator) sea Charts the Earth is not a sphere, but a square.

Composite Sailing Combines th advantages of the Great Circle and the Rhumb Line: It will be offer the shortes possible route and the vessel can keep constant true directions.

Due to infuences of the wind and current The Vessels destination will not be reached without any Alternations Of Course.

By Course Made Good is understood the course that the ship will follow after allowing for the effects caused by wind. Now the effect of the current on the vessels path must olso connected, resulting in a Course Over Ground that will lead to destination.